I use Linux servers mostly, but about a year ago I installed openSuSE on two new desktops. The problem was that, while sound "worked" in general, only one application could use the sound card at a time. That means when you have your audio player open, Youtube won't work at the same time. You'd have to close both apps and then re-open the browser so it could then hog the audio.
The most annoying thing about this, however, were some of my desktop Linux friends who insisted this behavior was totally acceptable and not a bug.